Solid ink jet printers were first offered commercially in the mid-1980""s. One of the first such printers was offered by Howtek Inc. which used pellets of colored cyan, yellow, magenta and black ink that were fed into shape coded openings. These openings fed generally vertically into the heater assembly of the printer where they were melted into a liquid state for jetting onto the receiving medium. The pellets were fed generally vertically downwardly, using gravity feed, into the printer. These pellets were elongated and tapered on their ends with separate rounded, five, six, and seven sided shapes each corresponding to a particular color.
Later solid ink printers, such as the Tektronix Phaser(trademark), the Tektronix Phaser(trademark) 300, and the Jolt printer offered by Dataproducts Corporation, used differently shaped solid ink sticks that were either gravity fed or spring loaded into a feed channel and pressed against a heater plate to melt the solid ink into its liquid form. These ink sticks were shape coded and of a generally small size. One system used an ink stick loading system that initially fed the ink sticks into a preload chamber and then loaded the sticks into a load chamber by the action of a transfer lever. Earlier solid or hot melt ink systems used a flexible web of hot melt ink that is incrementally unwound and advanced to a heater location or vibratory delivery of particulate hot melt ink to the melt chamber.
Basic configurations of a four-color ink loader having independent melt plates have been described in previously issued patents such as, for example, U.S. Pat. Nos. 5,734,402, 5,861,903, and 6,056,394. The disclosures of these patents are hereby incorporated by reference in their entirety.
Embodiments include an ink stick push block for use in a system for feeding solid ink sticks into a phase change printer, wherein each solid ink stick has an ink stick face surface having an ink stick face surface contour and an ink stick rear surface having a nonplanar ink stick rear surface contour. The push block includes an ink stick push block face having a nonplanar ink stick push block face contour, wherein at least a portion of the nonplanar ink stick push block face contour is the complement of at least a portion of the nonplanar ink stick rear surface contour.
Embodiments also include a solid ink loader for use with a phase change ink printer, which includes a first feed channel for receiving a first type of solid ink stick having a first rear surface having a first ink stick rear nonplanar contour and a first ink stick push block in the first feed channel, wherein the first feed channel has an entry end and an exit end, the first ink stick push block has a first push block face surface, the first push block face surface of the ink stick push block has a first push block face nonplanar contour, and the first push block face surface is at least partially the complement of the first ink stick rear nonplanar contour.